That seems very specific to your computer. Any reason not to leave it plugged in to the port it favors?
Not really
There are many that mention this issue
It seems an old story linked to Windows 10
https://www.reddit.com/r/Reaper/comments/127rkkg/why_is_my_nanokontrol2_so_messed_up/
And all other MIDI devices work with Ableton, so the problem is not just my system
No reason, but it may happen: the number of ports in my PC is not infinite, and I attach many things here and there
If it uses the temporary drive letter Windows assigns, just change it in Drive Manager to whatever letter it was originally.
I forgot that port 
Way easier to use the other controller that works without issues